Improved machine for cutting crystals



UNITED STATES PATENT OFFICE..

PAUL PRYIBIL, OE NEWv YORK, N. Y., ASSIGNOR TO HIMSELF AND GEORGESCHEIFFELE, OE SAME PLACE.

IIVIPROVED MACHINE FOR CUTTING CRYSTALS.

Specification forming part of Letters Pa'tent No. 36,548, datedSeptember 23, 1862.

section of this invention, the line a: x, Fig. 2,

indicating the plane of section. Fig. 2 is a longitudinal verticalsection of the same, taken in the plane indicated by thc line y y, Fig.3. Fig. 3 is a plan or top view of the same.

Similar letters of reference in the three views indicate correspondingparts.

This invention consists, first, in the arrangement of an adjustableinclined revolving shaft carrying a suitable clamp for the crystals, incombination with a grindingstone revolving on a horizontal shaft in sucha manner that by changing the inclination of the clamp-shalt theposition-of the clamp is adjusted according to the size of the stone andaccording to the size and shape of the crystal to be cut, and that eachstone can be used up down to the very anges which secure it to theshaft; second, in the arrangement of a gaging-screw in combination withthe frame which forms the bearings for the clampshaft, and to which asliding motion can be imparted toward and from the grinding-stone insuch a manner that by means of said set screw the clamp can be adj ustedto different sizes of crystals; third, in the arrangement of a tippinghead provided with two or more set-screws and with a guideway for theframe of the clamp-shaft in such a manner that by raising or loweringthe rear end of said tipping head the clamp is moved toward or from thegrinding-stone, and that the crystal can be made to bear on the stoneunder the most desirable angle; fourth, in the arrangement of twoglobe-shaped elastic pads, one of which is iirnily secured to the upperend of the inclined clampshaft, while the second pad is attached to alongitudinally-sliding pivot opposite the first pad, in such a mannerthat by forcing the second toward the first pad a crystal placed betweenthem is rmly clamped, and at the same time by the peculiar shape of saidpads and by their elasticity the danger of breaking the crystal isobviated; fifth, in the employmentof a curved dat spring in combinationwith said elastic pads in such a manner that by the aid of said curvedspring the correct position of each crystal between the two pads isdetermined.

To enable those skilled in the art to make and use my invention, I willproceed to describe its construction and operation with reference to thedrawings.

Crystals or glasses for watchcases have to be cut on their edges, so asto render them perfectly round or circular, and also to chamfer the edgeottfor the purpose of facilitating its entrance into the grooved ringwhich forms the lid of the Watch-case. This operation of cutting theedges ot' the crystals is generallyperformed by hand, each crystal beingheld against the circumference of a revolving stone and tu'rned until itassumes the desiredshape. This operation requires great skill and accuracy, and the most skillful workman is unable to produce crystals withperfectly round edges. It has therefore been proposed to execute thiswork by the aid of a machine, the principal working parts of which are aseries of rotary chucks arranged round a grindingstone with a conicalgrinding surface or edge and revolving on a vertical arbor. The chucksconsist each of two cups of sheet metal lined with leather or some othersuitable material, and corresponding in shape to the shape of thecrystals to be cut. These cups rotate in frames which are arranged in aninclined position round the stone, and the crystals are secured betweensaid cups or chucks by means of screws,which serve to force the cupstogether. A rotary motion is imparted to said chucks by means of pulleysand belts or by gearwheels, and as the several chucks revolve thecrystals fastened between them by coming in contact with thegrinding-surface of the revolving stone are cut to t-he desired shape.The principal disadvantages of this arrangement are, in the tirst place,the employment of one and the same stone for cutting several crystalssimultaneously. This requires a comparatively large stone, and, besides,if the stone wears down an inch or two, it has to be thrown away, thusconsiderably increasing the first cost of the machine and rendering aheavy running expense for new stones inevitable. Besides this, theposition of the crystals toward the grinding-surface of the stone issuch that grooves are cut into the same after a short time, rendering itnecessary to turn off the stone at shortintervals, at a great loss oftime. Furthermore, by having the chucks arranged in a circle it isimpossible to place the machine in such a position that all the chucksreceive the proper light, except under a skylight,which is only found ina small minority ot' buildings. All these difculties are con1- pletelyobviated in my machine.

The stone A rotates on a horizontal shaft, B, to which a rotary motionis imparted by a belt, a, passing over pulleys b c, the pulley c beingsecured to the driving-shaft C'.

The crystals to be cut are secured between the globe-shaped elastic padsD D', the pad D being secured to the arbor E,which rotates in theinclined frame F, while the pad D' is attached to a pivot, E', whichrotates freely in the upper end of the frame F, and to which alongitudinally-sliding motion is imparted by means of the eccentriclever or knuckle G. A spring, d, catching into a groove in the upper endof the pivot E', raises the upper pad, D', whenever the knuckle isturned back. By using the globe-shaped elastic pads crystals ofdifferent shape and size can be clamped without danger of breakage,since said pads adapt themselves readily to the varying shape of thecrystals, whereas with metallic cupshaped chucks it is indispensable tohave diff'erent chucks for different crystals, since, if the concavityof the crystal exceeds 'that of the chuck,it rests with its center onthe lower cup, while the other cup bears on it at a greater or smallerdistance from the center, and if the concavify of the chuck exceeds thatof the crystal the reverse takes place. The upper cup bears on thecenter, while the crystal touches the lower cup at a greater or smallerdistance from the center. In both cases, when the cups are forcedtogether, the danger of breaking the crystal is imminent.

Another great advantage of my machine over the one previously proposedis derived from the use of the knuckle G. Vith the old machine a screwis used for forcing the cups together and the slightest carelessness ofthe operator causes a breakage of the crystal.

Vith the knuckle,on the other hand,the pads are forced togetherinvariably with the same power and to the same distance,and no danger ofbreaking a crystal by clamping it too hard can possibly arise.

In order to secure the crystals in the proper position between the padswithout loss of time, a curved spring, e, is secured to the frame F.

This spring must be made to suit the size of the crystals, and fordifferent sizes of crystals different springs have to be used. Vhen acrystal is placed between the pads D D', it is pushed up against theinner or concave side of the spring, and the clamp` is fastened. As thecrystal revolves the spring will give to any inequalities which mayoccur in the edge of said crystal, so that it does not interfere withthe operation of cutting.

The frame F is rigidly secured to a carriage, F', which slides insuitable ways in the head H, a hand-screw,f, being provided to impartmotion to said carriage. The'extentto which the frame F can be moved isdetermined by the set-screw g, which Vscrews into a log, g', rising fromthe carriage F', and the end of which strikes against a stationary bar,h. attached to upper surface of the head H. This set-screw determinesthe size to which the crystals are cut,and it enables the operator toadjust the frame F readily to crystals of different sizes.

The frame F, together with the head H, are placed in an inclinedposition toward the grinding-surface of the stone, and this inclina tioncan be changed, as may bedesired, by means of set-screws 11j, whichregulate the position of the head H. This head turns on asemi-cylindrical bead near to its inner edge, so that by raising theouter edge the upper part of the frame F, with the clamp D D', is thrownin toward the center of the stone. By these means the frame is adj ustedaccording t0 the size of the stone and according to the size of thecrystals and to thewidth of the facet or chamfer to be produced. Thestandard or block H', which supports the head H, is secured to thebed-plate I by means of screwbolts t*, which pass through slots it, sothat said block, with the head and frameF, can be moved closer to orfarther from the grindingstone; and, when it is desired, the block H maybe so arranged that it can be raised and lowered, which in some casesmay facilitate the adjusting of the frame F with the crystal.

A slow rotary motion is imparted to the clamp-arbor E by an endlessscrew, J, which is attached to a shaft, K, that has its bearing in abox, L, supported by a standard, M.

Said standard is secured to the bed-plate in such a manner that it canbe moved toward or from the arbor E, and the box L, which forms thebearing of the screw-shaft K, is secured to the standard by means of ascrew-bolt, j, which allows of adjusting said shaft in a horizontal orin an inclined position, as may be desired. The screw J gears into aworm-wheel, N, that is firmly secured to the arbor E, and thisworm-wheel N is made conical, as clearly shown in Fig. l of thedrawings, so that the same remains correctly in gear with the wormwheeleven if the inclination of the arbor E is changed. The manner in whichthe shaft K is hung also serves to enable the operator to change theposition of the screw J according to the varying position of theclamp-arbor. The employment of the endless screw and wormwheel isdesirable, because by these means a steady continuous strain 'is exertedon the arbor E, and that peculiar trembling or quivering motion whichthe crystal is liable to assume when the arbor is driven by ordinarycog-wheels or by belts and pulleys is avoided.

It is obvious that a series of grinding-stones may be applied to thesame Shaft, each stone being provided with its own clamp, so that oneperson is enabled to attend to four or more stones simultaneously.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

l. The arrangement of the adjustable inclined revolving shaft E,carrying the clamp D D', in combination with the stone A, rotating on ahorizontal shaft, B, constructed and operating in the manner and for thepurpose specified. Y

2. The arrangement ofthe gaging-screw g,in combination with the frame Fand with the adjusting-screw f, as and for the purpose described.

3. The arrangement of the tipping head H,

with two or more setscrews, y, in combina 'tion with the slidingcarriage F', attached to lVitn esses:

W. HAUFF, J. F. BUCKLE.

